Inductively heated multi-mode ultrasonic surgical tool

Abstract

Thermal, electrosurgical and mechanical modalities may be combined in a surgical tool. Potentially damaging effects in a first modality may be minimized by using a secondary modality. In one example, thermal hemostasis may thus help electrosurgical applications avoid the adverse tissue effects associated with hemostatic monopolar electrosurgical waveforms while retaining the benefits of using monopolar incising waveforms.

What is claimed is: 
     
       1. A multi-mode adjustable surgical tool comprising:
 a body configured to oscillate; 
 a conductor placed along at least a portion of the body the conductor having a cross-sectional diameter; 
 a ferromagnetic coating covering a portion of the conductor, the ferromagnetic coating have a thickness less than about 20 percent of the cross-sectional diameter of the conductor such that the ferromagnetic coating will not fracture when subjected to environmental temperature differentials which would cause a ferrite bead to fracture; and 
 a power source configured for delivering oscillating electrical energy to the conductor. 
 
     
     
       2. The multi-mode surgical tool of  claim 1 , wherein the body comprises an ultrasonic horn. 
     
     
       3. The multi-mode surgical tool of  claim 1 , wherein oscillating electrical energy delivered by the power source causes the body to oscillate and causes the ferromagnetic coating to heat. 
     
     
       4. The multi-mode surgical tool of  claim 3 , wherein the power source is configured to create a first signal for causing heating of the ferromagnetic coating and a second signal for driving the body to independently provide energy to oscillate the body and energy to heat the ferromagnetic coating. 
     
     
       5. The multi-mode surgical tool of  claim 4 , wherein the power source is configured to operate the first signal and the second signal during overlapping periods of time. 
     
     
       6. The multi-mode surgical tool of  claim 4 , wherein the power source is configured to operate the first signal and the second signal during separate periods of time. 
     
     
       7. The multi-mode surgical tool of  claim 1 , wherein the body has a bore. 
     
     
       8. The multi-mode surgical tool of  claim 7 , wherein the body has a plurality of bores. 
     
     
       9. The multi-mode surgical tool of  claim 8 , wherein a first bore of the plurality of bores is configured to aspirate and a second bore of the plurality of bores is configured to irrigate. 
     
     
       10. The multi-mode surgical tool of  claim 1 , wherein the power source further comprises power settings corresponding to desired tissue effects. 
     
     
       11. The multi-mode surgical tool of  claim 1 , wherein the ferromagnetic coating has a thickness between 0.05 micrometers and 500 micrometers. 
     
     
       12. The multi-mode surgical tool of  claim 11 , wherein the ferromagnetic coating has a thickness between 1 micrometer and 50 micrometers. 
     
     
       13. A multi-mode surgical tool comprising an ultrasonic transducer and a thermal element, the thermal element comprising a conductor having a cross-sectional thickness and a ferromagnetic coating disposed on the conductor, the ferromagnetic coating having a thickness of less than about 50 percent of the cross-sectional thickness of the conductor such that the thermal element may be heated and immersed in liquid while still heated without fracturing. 
     
     
       14. The multi-mode surgical tool of  claim 13 , wherein the ultrasonic transducer further comprises a piezoelectric transducer. 
     
     
       15. The multi-mode surgical tool of  claim 13 , further comprising a power source for generating a multiplexed signal. 
     
     
       16. The multi-mode surgical tool of  claim 15 , wherein the multiplexed signal comprises an ultrasonic signal. 
     
     
       17. The multi-mode surgical tool of  claim 16 , wherein the multiplexed signal comprises an inductive heating signal. 
     
     
       18. The multi-mode surgical tool of  claim 17 , wherein the inductive heating signal is between 5 MHz and 24 GHz. 
     
     
       19. The multi-mode surgical tool of  claim 18 , wherein the inductive heating signal is between 40 MHz and 928 MHz. 
     
     
       20. The multi-mode surgical tool of  claim 13 , wherein the cross-sectional thickness of the conductor of between 0.01 millimeters and 1 millimeter and wherein the ferromagnetic coating has a thickness of between 0.05 micrometers and 500 micrometers. 
     
     
       21. The multi-mode surgical tool of  claim 20 , wherein the ferromagnetic coating has a thickness between 1 micrometer and 50 micrometers. 
     
     
       22. The multi-mode surgical tool of  claim 13 , wherein the electrical conductor has a cross-sectional thickness of between 0.01 millimeters and 1 millimeter and wherein the ferromagnetic coating has a thickness of between 1 micrometer and 50 micrometers. 
     
     
       23. The multi-mode surgical tool of  claim 22 , wherein the thickness of the ferromagnetic coating is between 0.1 and 20 percent the cross-sectional thickness of the electrical conductor. 
     
     
       24. A multi-mode surgical tool comprising:
 a tip comprising:
 an electrical conductor; 
 an ultrasonic transducer; and 
 a ferromagnetic coating covering at least a portion of the electrical conductor, the ferromagnetic coating having a thickness between 0.05 micrometers and 500 micrometers, and wherein the thickness of the ferromagnetic coating is between about 0.1% and 20 percent of a cross-sectional diameter of the electrical conductor. 
 
 
     
     
       25. The multi-mode surgical tool of  claim 24 , further comprising means for generating a multiplexed signal. 
     
     
       26. The multi-mode surgical tool of  claim 24 , comprising an oscillating body and wherein the tip is part of the oscillating body. 
     
     
       27. The multi-mode surgical tool of  claim 26 , wherein the oscillating body further comprises an ultrasonic horn. 
     
     
       28. The multi-mode surgical tool of  claim 24 , wherein the oscillating body comprises an aspirating bore. 
     
     
       29. The multi-mode surgical tool of  claim 24 , wherein the cross-sectional diameter of the electrical conductor is between 0.01 millimeters and 1 millimeter and wherein the thickness of the ferromagnetic coating is between 0.05 micrometers and 200 micrometers. 
     
     
       30. The multi-mode surgical tool of  claim 29 , wherein the thickness of the ferromagnetic coating is such that the ferromagnetic coating will not fracture when heated in air and then immersed in liquid while still heated. 
     
     
       31. A multi-mode surgical tool comprising:
 a lesioning probe having a tip comprising an electrical conductor and a ferromagnetic coating covering a portion of the electrical conductor; and an ultrasonic transducer, wherein the ferromagnetic coating is less than 50 micrometers thick and capable of being heated and then immersed in liquid while heated without cracking. 
 
     
     
       32. The multi-mode surgical tool of  claim 31 , further comprising a power source configured for delivering an oscillating current to the tip. 
     
     
       33. The multi-mode surgical tool of  claim 32 , further comprising a second tip, wherein the second tip comprises a sensor. 
     
     
       34. The multi-mode surgical tool of  claim 33 , wherein the power source is configured to react to the sensor. 
     
     
       35. The multi-mode surgical tool of  claim 33 , wherein the sensor is configured to measure temperature. 
     
     
       36. The multi-mode surgical tool of  claim 33 , wherein the sensor is configured to measure transferred heat. 
     
     
       37. The multi-mode surgical tool of  claim 33 , wherein the sensor is configured to measure tissue properties. 
     
     
       38. The multi-mode surgical tool of  claim 33 , wherein the sensor is configured to allow visual observation of tissue. 
     
     
       39. The multi-mode surgical tool of  claim 32 , wherein the power source is configured to measure a temperature indicator of the ferromagnetic coating and adjust an output to maintain a predetermined therapeutic temperature range in tissue. 
     
     
       40. The multi-mode surgical tool of  claim 31 , where the tip of the multi-mode surgical tool is coated with a thin layer of high temperature resistant, non-stick material. 
     
     
       41. The multi-mode surgical tool of  claim 31 , where the tip of the multi-mode surgical tool is covered by a thermally conductive, biocompatible material. 
     
     
       42. A thermally adjustable multi-mode surgical tool comprising:
 a cable; 
 a small diameter electrical conductor having a proximal and distal end, the small diameter electrical conductor having a cross-sectional diameter wherein the proximal end is configured to receive radiofrequency energy from the cable; 
 a thin plating of ferromagnetic material disposed circumferentially about the small diameter electrical conductor, wherein the thin plating of ferromagnetic material is configured with a Curie point sufficiently high to encompass a desired set of therapeutic temperature ranges, the thin plating of ferromagnetic material having a thickness of less than about 20 percent the cross-sectional diameter of the small diameter electrical conductor; and 
 an ultrasonic element connected to and configured to receive power from the cable and configured to release ultrasonic energy into nearby tissue. 
 
     
     
       43. The thermally adjustable multi-mode surgical tool of  claim 42 , wherein the electrical conductor has a cross-sectional thickness of between 0.01 millimeters and 1 millimeter and wherein the ferromagnetic coating has a thickness of between 0.05 micrometers and 200 micrometers. 
     
     
       44. The thermally adjustable multi-mode surgical tool of  claim 43 , wherein the thickness of the ferromagnetic coating is between 1 micrometer and 50 micrometers.